Downcoiler mandrel of the toggle link type for hot strip mills

ABSTRACT

A downcoiler mandrel is described, in which the mandrel segments and mandrel body have recesses or pockets in which semicylindrical bearings are mounted, in which the ends of toggle links are pivotally received. The links are provided with pin areas in which bushings are mounted, and the pins are locked against axial displacement. The bearings and bushings are made of preselected materials. Means are also provided for anchoring the bearings in the pockets or recesses.

nited States Patent 1 1 1 1 11 9 Noll et a1. Get. 9, 197? DOWNCOILER MANDREL OF THE 2,958,927 11/1960 Kravats 29/1495 NM TOGGLE LINK TYPE FOR HOT STRIP 1,444,628 2/1923 Miller 29/401 MILLS 75 Inventors: Stanley Darwin Noll, Shaker Primary Examiner-Charles Lanham Heights; William F, Delfeld, Assistant Examiner-Robert M. Rogers Lyndhurst, both of Ohio [73] Assignee: Production Experts, Inc., Cleveland, 57 ABSTRACT Ohio [22] Filed: Mar. 31, 1972 21 Appl. No.: 240,205

Related US. Application Data [62] Division of Ser. No. 17,828, March 9, 1970, Pat. No.

[52] US. Cl. 72/148, 242/72 [51] Int. Cl. B21lc 47/00 [58] Field of Search 72/148; 242/72 [56] References Cited UNITED STATES PATENTS 2,711,862 6/1955 l-lerr 242/72 A downcoiler mandrel is described, in which the mandrel segments and mandrel body have recesses or pockets in which semicylindrical bearings are mounted, in which the ends of toggle links are pivotally received. The links are provided with pin areas in which bushings are mounted, and the pins are locked against axial displacement. The bearings and bushings are made of preselected materials. Means are also provided for anchoring the bearings in the pockets or recesses.

7 Claims, 10 Drawing Figures PATENTED BET 91975 SHEEI 10F 4 2 Q0. wQNN Q v.

PAIENIEU 9W5 3.763 684 SHEET 30F 4 Fig. 7

DOWNCOILER MANDREL OF THE TOGGLE LINK TYPE FOR HOT STRIP MILLS This is a division of application, Ser. No. l7,828, filed Mar. 9, I970, now U.S. Pat. No. 3,672,030.

The invention is directed primarily to the repair and reconstruction of worn downcoiler mandrels of the type in which toggle links are employed to interconnect the mandrel body with surface segments of the mandrel and in which the links are activated to expand and contract the mandrel.

The invention will be best understood by reference to the accompanying drawings, forming a part of this application, and in which FIG. I is a fragmentary longitudinal cross-sectional view of a typical or conventional downcoiler mandrel of the type which utilizes toggle links for expanding the segments, and with the mandrel in expanded condition;

FIG. 2 is a vertical or transverse cross-sectional view, taken on the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary vertical or transverse crosssectional view, taken on the line 3--3 of FIG. 1;

FIG. 4 is a vertical or transverse cross-sectional view, taken on the line 4-4 of FIG. 1, but with the mandrel in collapsed condition;

FIG. 5 is a fragmentary cross-sectional view, taken on the line 5-5 of FIG. 4;

FIG. 6 is a fragmentary cross-sectional view, similar to FIG. 5, but showing a construction of the link and assciated parts, embodying the invention;

FIG. 7 is a fragmentary cross-sectional view, taken on the line 7-7 of FIG. 6;

' FIG. 8 is a plan view showing the manner in which the mandrel segment half bushing or insert is held in position in the mandrel segment;

FIG. 9 is a fragmentary cross-sectional view, taken on the line 9-9 of FIG. 8, and

FIG. 10 is a fragmentary cross-sectional view, taken on the line 10-10 of FIG. 9.

Referring more particularly to FIGS. 1 to 5 inclusive of the drawings, the downcoiler mandrel is seen to comprise a mandrel body I of the general crosssectional configuration shown in FIGS. 2, 3 and 4, and mounted for rotation in bearings 2, which, in turn, are mounted within a stationary cylindrical housing 3, supported by a pedestal or base 5.

The mandrel further comprises four segments 6, 7, 8 and 9, which surround the mandrel body 1 and are of substantially similar construction, the outer surfaces of these segments constituting, in effect, a substantially continuous cylindrical surface, on which hot strip received from a strip mill is continuously wound or reeled to provide a coil of such strip, which is subsequently removed from the mandreL' The strip is wound on the mandrel while the mandrel segments are in their expanded condition or position, as shown in FIGS. 2 and 3, but in order to facilitate removal of the coil of strip from the mandrel, the mandrel segments must be collapsed to the position or condition shown in FIG. 4. I

For the purpose of effecting expansion and collapsing movement of the mandrel segments, rows of toggle links 10 are provided, which pivotally interconnect the mandrel segments with the mandrel body, the links in each row being uniformly spaced longitudinally from each other, and also arranged in parallelism with each other, as best shown in FIG. I.

The segments, as previously stated in connection with FIG. I, are in their expanded condition, so that in order to move the segments to their collapsed position, as shown in FIG. 4, it is necessary to move the segments from the position shown in FIG. I to the right until the segments occupy the position shown in FIG. 4. This collapsing movement is effected by a rocking movement of the outer portions of all of the toggle links 10 toward the right, from the position shown in FIG. I.

This movement of the segments to the right is effected by means of a shaft II, which extends through the center of the mandrel body 1, and has keyed to one end thereof an actuator or disc 12, the peripheral position of which extends into recesses 13 adjacent the ends of the mandrel segments. Thus, when the shaft 11 is moved toward the right from the position shown in FIG. 1, the segments are simultaneously moved to the right by the disc 12. At the same time, the segments slide over the front and rear surfaces of the disc I2, so that the axial movement of the disc for the purpose of collapsing or expanding the segments can be effected without interfering with the rotation of the mandrel body and segments.

Referring more particularly to FIGS. 1, 4 and 5, the toggle links 10 are of flat dog bone shape, having a central body portion 14 and end portions 15 and 16 of cylindrical shape, the portion 15 having a central or axial opening 17, and the portion 16 having a central or axial opening.

The end portion 15 of each link is mounted or seated for pivotal movement in a pocket or recess 20 in the segment, which recess has an arcuate bottom 2ll conforming to the outer surface of the portion 15 of the link.

through the axial opening 17 of the link, and the ends of which are mounted in aligned openings 23 and 24 in the segment, which openings are of the same diameter as the opening 17. The pin 22 has a threaded head 25, which is threaded into the segment, so that the pin 22 can be removed, when necessary.

The end portion 16 of the link 10 is mounted or seated for pivotal movement in a pocket or recess 26 in the mandrel body 1, which recess has an arcuate bottom 27 conforming to the outer surface of the end portion 16.

The end portion 16 of the link 10 is mounted for pivotal movement about a steel pin 28, which extends through the axial opening 18 of the link, and the ends of which are mounted in aligned openings 29 and 30 in the mandrel body, which openings are of the same diameter as the opening 18. The pin 28 is retained against axial displacement by means of a retainer plate 31, disposed in a recess 32 of the mandrel body, and secured to the mandrel body by means of hollow head screws 32a.

The peripheral contour of this plate 31 is indicated in broken lines in FIG. 1 and in solid lines in FIG. 5. The pin 28 may be removed by first removing the plate 31.

Passageways 33 and 34 in the segment and mandrel body respectively, are provided, as shown in FIG. 4, for admitting an oil lubricant or the like to the ends of the link 10, to reduce wear of these parts as well as the parts of the segment and mandrel adjacent the link.

The end portion 15 of the link 10 is mounted for pivotal movement about a steel pin 22, which extends Some of this lubrication also reaches the pins 22 and 28.

Due to the metal to metal contact of the links with the mandrel body and segments, as well as the metal to metal contact of the pins 22 and 28 with the links and the mandrel body and segments, continued use of the mandrel causes rapid wear of the links, the surfaces against which they bear, the pins, and the surfaces against which the pins bear, necessitating frequent replacement of links and pins, as well as repair of the worn surfaces of the mandrel body and segments. This repair is usually accomplished through the use of welding overlays, followed by machining or removal of excess overlay and subsequent heat treatment to relieve stresses developed during the welding.

This stress-relieving process frequently causes distortion of the mandrel body, as to its axial straightness, and this distortion, in turn, adversely affects the lift of the bearings 2 in which the mandrel body rotates.

The lubrication to which reference has been made is accomplished through the use of various petroleum products, such lubrication procedure not only requiring the use of personnel for performing the lubrication, but also resulting in frequent malfunctioning caused by improper lubrication, due either to insufficient frequency of lubrication, or to improperdist ribution of the lubricant within the mandrel body and segments.

The foregoining replacements and repairs, and malfunctions due to improper lubrication, require frequent shut-downs of the mill, disassembly of the mandrel, reassembly, etc., all of which is time-consuming as well as expensive.

The present invention has, as its primary object, a novel method of repairing mandrels of the character described, which not only greatly reduces or virtually eliminates wear of the mandrel body, segments, links and pins, but also obviates the need for use of welding overlays and removal of excess overlay, as well as the subsequent heat treatment and resulting distortion or deformation of the mandrel body.

Another object of the invention is to provide a repair method of the character described, involving the use of bushings and half-bushings or inserts of preselected materials, for interposition between the toggle links and mandrel body and segments, and between the toggle pins and links and mandrel body and segments, such that wear of the character hereinbefore described, as well as the need for frequent replacement and repair, is obviated or reduced to a minimum.

A further object of the invention is to provide for the use of bushings and half-bushings or inserts of the character described, and for the purposes stated, made of pre-selected materials, such that little or no lubrication is required for facilitating movement of the toggle links, or, if some lubrication is required, the lubrication can be effected in a uniform manner, at infrequent intervals, and without causing malfunctioning arising from normal lubrication procedures.

A further object of the invention is to provide a mandrel construction, particularly with reference to the toggle links and associated parts, which is applicable to the manufacture of new mandrels, in addition to the repair of old, worn or used mandrels.

A still further object of the invention is to provide toggle links of the character described, having wear surfaces which are electroplated at selected areas thereof with materials which are conducive to easier sliding movement of the toggle links and which tend to reduce the wear of and preserve the life of the links.

These, as well as other objects, are accomplished in the manner which is best shown in FIGS. 6 to 10 inclusive of the drawings.

On the assumption that wear of the mandrel shown and described with reference to FIGS. 1 to 5 inclusive, has occurred, to an extent requiring repair or rehabilitation of the area of the mandrel in and adjacent the toggle links and their connections to the mandrel body and segments, the mandrel is disassembled, and repairs made in a manner to be now described.

The recess 20 in the mandrel segment is enlarged by a boring operation to a diameter such that it can accommodate a half-bushing or insert to be presently described. This is illustrated in FIGS. 6 to 10, where it is shown that holes or openings 40 and 41 are provided in the mandrel segment for the reception of dowel pins 43, and threaded holes 44 and 45 are also provided for the reception of hollow head cap screws 46, the openings 44 and 45 being counterbored at their upper ends, as at 47, to provide space for the heads of such screws.

An insert or half bushing 48 is then placed within the enlarged recess 20, and is locked against endwise displacement by means of the dowel pins 43 which extend through the half bushing and into the holes 40 and 41, and locked to the segment by means of the cap screws 46 secured in the threaded holes 44 and and 45 and the caps of which are disposed in the counterbores 47 and bear against shoulders 49 on the half bushing.

The half-bushing or insert 48 is preferably made of bronze or other non-ferrous metal having hardness and wear properties similar to bronze, although, in some cases, a ferritic material, such, for example, as Ferro- Tic, which is a powder metal composite of hard titanium grains cemented by an alloy tool steel matrix, may be employed for making the insert. The general or generic term metallic will be used hereinafter to encompass such materials, and to distinguish them from certain parts made of non-metallic materials, to which reference will presently be made.

The half-bushing or insert 48 is of a thickness, for example, three-eighths inch, such as to substantially fill the space between the englarged recess 20 and the end of a toggle link of conventional size or dimensions.

New toggle links 50 are provided having their arcuate end surface portions 51 and 52 electroplated with chromium, to provide hard, wear-resistant surfaces.

The portions of the links 50 corresponding to the end portions 15 and 16, which have previously been described, are provided with central or axial openings 53 and 54, corresponding respectively to the previously described openings 17 and 18, but of enlarged diameter, so as to accommodate bushings 55 and 56. The bushing 55 is preferably made of the same material as the half-bushing or insert 48.

The openings 23 and 24 in the segment (see FIG. 4) are enlarged to the same diameter as the opening 53, to accommodate bushings 57 and 58, preferably made of the same material as the bushing 55 and the halfbushing or insert 48.

A steel pin 59 corresponding to the pin 22 is then inserted through the bushings 55, 57 and 58, and may be resin or plastic having properties similar to Nylon, as, for example, certain grades of Teflon. In some case, a

metallic material impregnated with such synthetic resin hardness and wear properties similar to those of Nylon. 7

The general or generic term non-metallic will be used hereinafter to encompass such materials, and to distinguish them from the materials of which the parts $8, 55, 57 and 58 are made.

The openings 29 and 30 in the mandrel body (see FIG. 4) are enlarged to the same diameter as the opening 54, to accommodate bushings 61 and 62, which are made of the same material as the bushing 56.

The recess 26 in the mandrel body is enlarged by a boring operation to a diameter such that it can accommodate a half-bushing or insert 63, made of the same material as the bushings 56, 61 and 62, and provided with a semi-circular end flange 64, the outer surface 64a of which is substantially flush with the outer end surface of the link 50.

A steel pin 65, corresponding to the pin 28, is then inserted through the bushings 61, 56 and 62, and the pin, the bushings, half-bushing and link are then secured in position, or against displacement, as by means of a plate 66, which is secured to the mandrel body 1 by means of hollow headed cap screws 67.

Provision may also be made for lubricating the toggle links and adjacent areas, through passageways (see FIGS. 8, 9 and 10) in the mandrel segments, and similar provisions may be made in the mandrel body for lubricating those portions of the links which are disposed in the mandrel body.

By repairing the mandrel in this manner, not only is wear of the critical parts and areas which have been described, greatly reduced or virtually eliminated, but the need for use of welding overlays and removal of excess overlay, as well as the subsequent heat treatment and resulting distortion or deformation of the mandrel body, is obviated.

The use of bushings and half-bushings or inserts of the selected materials, which have been described, greatly reduces wear, as well as the need for frequent replacement and repair, and the need for excessive lubrication. Moreover, these materials, being softer than the material of the mandrel body, mandrel segments, and linkage pins, absorb shocks, and, to some extent, become slightly deformed during use. However, this deformation of the bushings, etc., rather than other parts of the mandrel, eliminates the need for machining portions of the mandrel and segments, when the bushings and half-bushings are to be replaced.

The toggle links are produced from an alloy steel, heat treated and hardened to insure extended life of the links by confining the wear to the areas in which the bushings are mounted, and to the plated areas which can be worked without difficulty at the time of rebuilding. Where new toggle links are employed, these may 7 be provided with built-in bushings at the pin-receiving openings or areas.

Although the invention has been described more particularly with reference to a method or methods of repairing or rehabilitating mandrels which have been in use, it will be readily understood that the invention is also applicable to the construction of new mandrels, or to the replacement of old and worn mandrels by new mandrels incorporating the construction which has been described.

Moreover, although the insert or half-bushing 48, and bushings 55, 57 and 58 in the mandrel segment have been described as made of selected metallic materials, it is to be understood that under certain conditions, it may be desirable to make these of materials hereinbefore referred to or described generally or generically as nonmetallic" materials, and the use of such non-metallic materials for such inserts or halfbushings and bushings is deemed to fall within the scope of this invention.

It is to be understood that the form of our invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes may be made in the shape, size and arrangement of parts thereof, without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described our invention, we claim:

1. In a strip coiler, a mandrel body, mandrel segments disposed about said body, said segments having recesses therein having semi-cylindrical bottoms, semicylindrical bearing members in said recesses, said mandrel body having recesses therein having semicylindrical bottoms, semi-cylindrical bearing members in said mandrel body recesses, means for moving saig segments relatively to said body, said means comprising toggle links interposed between said body and segments, pivot pins interconnecting said links with said body and segments, said links having end portions pivotally movable relatively to said body and said segments, and seated in the bearings of said segments and body, and means for anchoring said mandrel segment bearings in said segments, said last-named means comprising removable fasteners engaging the marginal edges of said mandrel segment bearings and extending tangentially of said mandrel segment bearings and into said mandrel segments.

2. A strip coiler, as defined in claim 1, wherein the bearing members between said links and said segments are made of metallic material, and the bearing members between said links and said body are made of nonmetallic material.

3. A strip coiler, as defined in claim 2, wherein bushings are interposed between said pins and said links, and body and segments.

4. A strip coiler, as defined in claim 3, wherein the bushings interposed between said pins and said links and segments, are composed of a metallic material, and

the bushings which are interposed between said pins and said links and mandrel body are composed of a non-metallic material.

5. A strip coiler, as defined in claim 4, wherein said toggle links are of dog bone" contour having a narrow neck portion and enlarged cylindrical end portions, and said pins extend through the axes of said end portions.

6. A strip coiler, as defined in claim 1, including means for anchoring said pins against axial movement.

7. A strip coiler, as defined in claim 6, wherein said semi-cylindrical bearing members in said body recesses have end flanges, and means are provided for removably securing said flanges to said mandrel body.

4 =0: e t a 

1. In a strip coiler, a mandrel body, mandrel segments disposed about said body, said segments having recesses therein having semi-cylindrical bottoms, semi-cylindrical bearing members in said recesses, said mandrel body having recesses therein having semi-cylindrical bottoms, semi-cylindrical bearing members in said mandrel body recesses, means for moving said segments relatively to said body, said means comprising toggle links interposed between said body and segments, pivot pins interconnecting said links with said body and segments, said links having end portions pivotally movable relatively to said body and said segments, and seated in the bearings of said segments and body, and means for anchoring said mandrel segment bearings in said segments, said last-named means comprising removable fasteners engaging the marginal edges of said mandrel segment bearings and extending tangentially of said mandrel segment bearings and into said mandrel segments.
 2. A strip coiler, as defined in claim 1, wherein the bearing members between said links and said segments are made of metallic material, and the bearing members between said links and said body are made of non-metallic material.
 3. A strip coiler, as defined in claim 2, wherein bushings are interposed between said pins and said links, and body and segments.
 4. A strip coiler, as defined in claim 3, wherein the bushings interposed between said pins and said links and segments, are composed of a metallic material, and the bushings which are interposed between said pins and said links and mandrel body are composed of a non-metallic material.
 5. A strip coiler, as defined in claim 4, wherein said toggle links are of ''''dog bone'''' contour having a narrow neck portion and enlarged cylindrical end portions, and said pins extend through the axes of said end portions.
 6. A strip coiler, as defined in claim 1, including means for anchoring said pins against axial movement.
 7. A strip coiler, as defined in claim 6, wherein said semi-cylindrical bearing members in said body recesses have end flanges, and means are provided for removably securing said flanges to said mandrel body. 